Yamamoto

A-08 that is the antecedent of this A-08S was evaluated very highly among the mania of the single amplifier of the vacuum tube, for instance, receive high evaluation since the launching and receive the SOTA prize in Internet audio magazine 6moons of U.S.A There are many one that are combined with the high efficiency speaker such as the ALTEC and LAWTHER into one of the user, although it was becoming the bestseller of No.1 among the product of our company and be desiring and be making lower the remaining noise and was receiving the request a lot. The quality of the sound at the time of the small signal is important' in a high efficiency speaker it is thought that it was the vacuum tube that 45' of the tone quality were suited to those request most. There is the characteristic that the high efficiency speaker appears largely as it is even the noise not only the music signal. Therefore the noise level needs to be held down over a general amplifier.

INFORMATION TAKEN FROM YAMAMOTO SOUND CRAFT
HA-02 is the headphone amplifier which uses a vacuum tube as an amplification element. Although output power is small, it has the output terminal for speakers and it can also sound a speaker with small volume as BGM.
Only one right and left are using each the miniature vacuum tube 408A of a Western Electric for an amplification tube. Although this WE408A is a vacuum tube of a vintage, it is one of the produced vacuum tubes, and since it was used abundantly for telefon equipment, there are no worries about a spare tube even now. It seems that it was used for various uses in order to often tend to use characteristics, although this vacuum tube is originally designed as an object for high frequency amplification. When it was used for the data of a Western Electric as a small output tube, there was description that about 300mW output power was obtained. When we manufactured the amplifier for headphone based on this description, we decided to produce commercially, since the good result was obtained.

It is the optimal amplifier for a direction to use both headphone and a speaker.
HA-03 is the unique amplifier which designed headphone, of course aiming at the amplifier which can enjoy itself by the best sound quality also with the speaker.
The amplifier which can generally enjoy both headphone and a speaker in the optimal state is made difficult.
In this machine, I conquered the difficulty by using the highly efficient vacuum tube C3m with one-step composition.
As for vacuum tube amplifier, the simplicity of the composition appears in sound.
In the case of this machine, the charm which simplifies the composition to a limit and the vacuum tube has been pulled out to the maximum extent.
Since it is simple, freshness sound and music can be enjoyed.

Excerpt from 6moons review: The CA-04 line level preamplifier is based on the same circuit as the CA-03L full-function preamplifier with phono stage, but contains slightly different component parts choices to hot-rod performance while the chassis sports a Japanese Cherry fascia with African Ebony knobs. Brian adds that "in terms of sonics, the CA-04 sounds almost identical to the CA-03L, although it may be a tad more neutral. You'd really have to do lots of back-and-forth comparisons to hear the difference." The CA-04 uses hand-selected Telefunken 6AK5W (5654) pentodes chosen for their superior tone when used in this preamplifier's zero NFB circuit. Note this detail: The capacitors are mounted in African Ebony cases filled with a special Yamamoto epoxy blend claimed to give improved tone over conventionally mounted capacitors. Gain is 16dB and the frequency response ± 0.5dB from 10Hz - 150 KHz.